Author: Nakamura, N.
Paper Title Page
MOP1WB03 Current and Future of Storage Ring Based Light Sources in KEK 17
 
  • N. Higashi, K. Harada, T. Honda, Y. Kobayashi, N. Nakamura
    KEK, Ibaraki, Japan
  • K. Hirano
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
  
  KEK has two stor­age-ring light sources. One is Pho­ton Fac­tory (PF). This is the first stor­age-ring light source in X-ray re­gion in Japan, and the user-run started in 1983. The ring en­ergy is 2.5 GeV, and the emit­tance has been re­duced to 36 nm·rad from 460 nm·rad through some im­prove­ments. An­other is Pho­ton Fac­tory Ad­vanced Ring (PF-AR). The ring en­ergy is 6.5 GeV, and the sin­gle-bunch op­er­a­tion and hard X-ray are fea­tured. The user-run started in 1987, and the emit­tance is 293 nm·rad. The mag­netic lat­tice is al­most the same as the orig­i­nal one. Now we con­sider the fu­ture plans of KEK light sources. One is the fully new fa­cil­ity ap­ply­ing DQBA lat­tice, named KEK-LS. The cir­cum­stance is 571 m, and the emit­tance is 315 pm·rad @ 3 GeV and 500 mA. In par­al­lel with that, two plans of the only re­place­ments of the lat­tices reusing ex­ist­ing tun­nels of PF and PF-AR are con­sid­ered. For the PF up­grade, only the arc lat­tice will be re­placed with a new lat­tice em­ploy­ing com­bined bends, and the emit­tance will be im­proved to 8 nm·rad from 35 nm·rad. For the PF-AR up­date, fully re­place­ment will be car­ried out with a new HMBA lat­tice, and the ex­pected emit­tance is 520 pm·rad @ 3 GeV and 500 mA.  
slides icon Slides MOP1WB03 [7.488 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-MOP1WB03  
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THP1WB02 Impedance Evaluation of PF In-Vacuum Undulator (IVU) with Theories and Simulations and Experimental Confirmation of them by the Tune Measurement 160
 
  • O. Tanaka, N. Nakamura, T. Obina, K. Tsuchiya
    KEK, Ibaraki, Japan
  
  Four In-Vac­uum Un­du­la­tors (IVU) were re­cently in­stalled to Pho­ton Fac­tory (PF) at KEK. The es­ti­mate of their im­ped­ance and kick fac­tors is a very im­por­tant issue, be­cause they could con­sid­er­ably in­crease the total im­ped­ance of PF. More­over, the cou­pling im­ped­ance of the IVUs could lead to the beam en­ergy loss, changes in the bunch shape, be­ta­tron tune shifts and, fi­nally, to the var­i­ous beam in­sta­bil­i­ties. Using the sim­u­la­tion tool (CST Par­ti­cle Stu­dio), lon­gi­tu­di­nal and trans­verse im­ped­ances of the IVUs were eval­u­ated and com­pared to an­a­lyt­i­cal for­mu­las and mea­sure­ment re­sults. The study pro­vides guide­lines for mit­i­ga­tion of un­wanted im­ped­ance, for an ac­cu­rate es­ti­mate of its ef­fects on the beam qual­ity and beam in­sta­bil­i­ties and for the im­ped­ance bud­get of a newly de­signed next-gen­er­a­tion ma­chine which has many IVUs and small-aper­ture beam pipes.  
slides icon Slides THP1WB02 [2.942 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-THP1WB02  
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